This invention relates generally to switches for high speed circuits such as radio frequency switches.
In switches that operate at high speed, it is important that the switch itself does not unduly degrade the signal being switched. Insertion loss is a measure of signal degradation caused by a switch. Insertion loss is dominated by the dimple contact resistance. Generally, a cantilevered switch arm includes a dimple or hemispherical portion near its free or moving end which contacts a contact pad on a fixed structure.
To reduce the resistance in contact, soft metals are used for the dimples and large contact forces are often necessary to increase real contact area. Soft metals and large contact forces result in faster contact wear. As the contact wears, the reliability of the switch may be adversely affected.
Thus, there is a need for better ways to make switches for high speed circuits.